In honor of the Fourth of July and its celebration of freedom, espnW takes a look at notable declarations of independence in the sports world.

Billie Jean King and the "Original 9" declare tennis independence

Tennis is big business and the leading professional sport for women. But the WTA's success -- and the controversy over grunting and shrieking -- would not be possible without the actions of pioneer Billie Jean King and eight other female tennis players: Rosie Casals, Nancy Richey, Kerry Melville, Peaches Bartkowicz, Kristy Pigeon, Judy Dalton, Valerie Ziegenfuss and Julie Heldman. Dubbed the "Original 9," they changed the course of tennis history.

Tired of a separate and unequal landscape in which men controlled the tournaments and prize money for women was significantly less than for their male counterparts, King and her compatriots took the brave step of declaring independence in September 1970. They left what was then known as the U.S. Lawn Tennis Association and signed $1 contracts to play in the new Virginia Slims series. The Virginia Slims was the precursor of the WTA, which was established in 1973. How revolutionary was this step? Title IX, largely viewed as the turning point for the growth of women's sports in the United States, wasn't passed until 1972.

Curt Flood: Baseball's Patrick Henry

Love it or hate it, as soon as the World Series ends, the free-agent frenzy starts. But it wasn't always that way. It started with the act of one man who helped bring about a revolution in baseball. Scott Boras and his clients can thank Curt Flood, who sacrificed his career to help players achieve the economic freedom they take for granted today. Flood's revolutionary step is baseball's version of Patrick Henry's "Give me liberty, or give me death" speech.

Curt Flood's trade to the Phillies would change baseball history.

Flood was a three-time All-Star and seven-time Gold Glove winner as the center fielder for the St. Louis Cardinals in the 1960s. At the peak of his career, following the 1969 season, the Cardinals tried to trade Flood to the Philadelphia Phillies. Flood refused to accept the trade and decided to challenge baseball's "reserve clause," a provision in the standard player's contract that effectively tied a player to a team in perpetuity. Flood essentially demanded to become a "free agent," though that term did not exist then. When the commissioner refused his demands, Flood sued.

The lawsuit eventually reached the Supreme Court. Though the court ruled against Flood and upheld baseball's long-standing antitrust exemption, his unprecedented actions were the first step on the road to free agency. Major league baseball players achieved that goal in 1975 with the Messersmith-McNally ruling.

Spencer Haywood: NBA freedom fighter

LeBron James, Kobe Bryant, Dwight Howard, Kevin Garnett, Carmelo Anthony, Dwyane Wade and countless other NBA stars owe Spencer Haywood a huge debt of gratitude. Thanks to Haywood's groundbreaking lawsuit in 1970, each had the chance to take their talents to the NBA straight out of high school, or after fewer than four years of college.

Though many credit Darryl Dawkins and Moses Malone for being the early-entry pioneers -- they were the first two to play in the league out of high school -- it was Haywood, the original "man-child," and his lawsuit that made these future stars' early entries possible.

Haywood left the University of Detroit after his sophomore year and signed with the upstart ABA's Denver Rockets, where he led the league in scoring and rebounding in the 1969-70 season. The NBA's Seattle SuperSonics signed Haywood to a contract in 1970, ignoring the rule that required players to wait until four years after high school to join the league. The NBA tried to invalidate the contract and imposed sanctions on the team to prevent Haywood from playing. Haywood and the Sonics' owner responded with an antitrust suit challenging the rule as an illegal restraint of trade.

In 1971, the case reached the Supreme Court, where the justices upheld a lower-court ruling that preventing Haywood from playing in the NBA would cause him "irreparable injury in that a substantial part of his playing career will have been dissipated." Thanks to Spencer Haywood's groundbreaking actions, the "four-year rule" was abolished.

Canadian women's soccer team mutiny

The Canadian team's Women's World Cup matches weren't the first battles they fought this year. Off the pitch, the team engaged in a prolonged standoff with the Canadian Soccer Association over two issues that put the team on the brink of mutiny: coaching and compensation. In February, the players threatened to boycott all international competition after the World Cup if the CSA did not retain head coach Carolina Morace. Morace had announced she was leaving after the World Cup due to a philosophical disagreement with the CSA. The team also threatened to sue the CSA over what it believed to be unfair compensation, seeking a long-term deal and transparency in how compensation would be determined.

In early June, just weeks before the players took to the pitch in Germany, the CSA agreed to a new deal with Morace to keep her in place through the 2012 Summer Olympics. A day later, the team agreed to a two-year deal to resolve the pay dispute. Thanks to a unified front, the Canadians can get back to focusing their efforts on the pitch.

Breaking free from tennis dads

What is it about female tennis players and their fathers? Some have taken things to such an extreme that their daughters have had to take action to separate themselves. Most notorious is Jim Pierce, the father of Mary Pierce, who emerged on the tennis scene in 1989 at age 14. Mary became as well-known for her father as for her ability on the court.

Jim Pierce, who also happened to be Mary's coach, notoriously screamed obscenities at her and her opponents on the court, and Mary said he abused her physically. On Nov. 19, 1992, the Women's Tennis Council passed a rule -- referred to as the "Jim Pierce Rule" -- under which an agent, parent or coach can be banned from any or all tour events because of courtside conduct. In June 1993, the WTC invoked the rule to ban Jim Pierce from attending 1993 tour events as a result of violent behavior he exhibited at the 1993 French Open. Mary also had to engage a bevy of security guards and even filed several restraining orders against her father. He remained banned from the WTA Tour until 1998. Postscript: Mary and her father reportedly reconciled in the middle of last decade.